The present invention relates to a developing method and apparatus, more particularly, to such a method and apparatus wherein a developer is carried on a developer carrying member and opposed to a latent image bearing member with a clearance or gap therebetween at a developing station, where the developer is transferred from the developer carrying member to the latent image bearing member to visualize the image on the latent image bearing member.
It is known, for example, from U.S. Pat. Nos. 3,232,190, 3,866,574, 3,890,929 and 3,893,418, that the developer carrying member carrying a thin layer of a dry developer is opposed to the latent image bearing member at the developing station with a clearance therebetween which is larger than the thickness of the thin developer layer, and the developer is transferred through the clearance to the latent image bearing member, thus developing the latent image. Furthermore, it is also known from U.S. Pat. No. 4,395,476, that an alternating electric field is continuously formed in the clearance to cause repeated reciprocations, that is, transfer and back-transfer, of the developer particles in the clearance between the surface of the developer carrying member and the surface of the latent image bearing member. This will be called a "jumping development". This development is advantageous in that no foggy background is produced, that the tone reproducibility is good and that thin lines are acceptably reproduced.